Authorities have confirmed reports that a series of shootouts between drug cartel rivals has left behind blockades south of the border in Rio Bravo.
Rio Bravo is a city of 96,000 people located on Mexican side of the border just south of Donna, Texas.
Residents turned to the social media network Twitter to report gunfire between drug cartel rivals just before 8 a.m. Thursday.
Tamaulipas state officials confirmed on Twitter that a series of blockades are slowing traffic on the highway to Matamoros and other roadways.
Authorities have not released details but a photo of a burned out school bus from one of the blockades is circulating on Twitter and Facebook.
The gun battles come following another round of violence in nearby Nuevo Progreso and Valle Hermoso on Tuesday evening.
Investigators confirmed six armed men were killed during those gun battles.
Mercedes residents told Action 4 News that a Mexican military helicopter could be seen flying from the American side of the border.